| 摘要 |
PURPOSE:To detect interference up to a reception input level higher by the attenuation extent of a varaible attenuator by providing the variable attenuator between the 1st intermediate frequency filter and the 2nd mixer. CONSTITUTION:The variable attenuator 10 is provided between the 1st intermediate frequency filter 5 and the 2nd mixer 7. An output of the 2nd intermediate frequency filter 8 is inputted to an attenuator 10 via an amplifier 11 and a detector 12. Then the reception input level of the receiver and the output of the 2nd mixer 7 are shown in solid lines, and even when the reception input level reaches a level V1, the 2nd intermediate frequency component of the 2nd mixer 7 is not saturated and the output of the 2nd intermediate frequency component of the 2nd mixer 7 does not reach the saturation level before the reception input level reaches a level V2. Then the interference detector 9 is operated until the reception input level reaches the level V2. |
